Die



Sept. 5,v 1939. T. A. BowERs 2,172,044

. DIE

Filed Jan. 2, 19:57 4 sheets-sheet 3 Sept. 5, 1939. T. A. Bowl-:Rs

DIE

4 Smets-sheet 4' Filed Jan. 2, 1937 fejlo.

Patented Sept. 5, 1939 PATENT QFFICE DIE Thomas A. Bowers, Boston,Mass., assignor tov Power Research Corporation, Boston, Mass., acorporation of Massachusetts Application January 2, 1937, Serial No.118,864

8 Claims.

This invention relates to dies and more particularly to forming dies foruse in the manufacture of packing and piston rings formed from aplurality of metal pieces'. An example of one type of .piston ring isdisclosed in my co-pending application, Ser. No. 733,243, filed June 30,1934, for Piston ring material. The present application is a-continuation in part of my now pending application for Dies, Ser. No.20,738, filed March 10,

The principal object of my invention, therefore, is an improved-diestructure.

Another object is a diel structure comprising means for reducing thecircumference of a ring of material composed of loosely compacted foldsor sheaves of metal.

Another object is a device of the character described in which means areprovided for eliminating buckling of the ring material while being 20compressed.

Another object Vis a tapered forming structure for shaping the tops andsides of a fabricated packing ring.

Another object is the provision of means in a die for flowing orotherwise reacting on metal for a fabricated piston ring.

Other objects and novel features forming a part of the invention willappear as the description progresses. l n

In the drawings embodying my invention- 4 Fig. 1 is a verticalsymmetrical cross-section of the complete die in a loading position.

Fig. 2 is a fragmentary vertical cross section of the die in a loadingposition.

Fig. 3 illustrates a fragmentary cross section similar to Fig. l withthe head of the die dropped down to a contact position. Y

Fig. 4 is a View similar to Figs. 1 and 2 showing the die in a finallyclosed position.

Fig. 5 is a view in fragmentary cross sectionk similar to Figs. 1-3inclusive and illustrating the die raised after the completion of anoperation.

Fig. 6 is a fragmentary vertical cross section of ,a modied type of dieconstruction illustrating plate holding means in elevation andindicating the reduction of a ring vfrom one die size to another smallerdie size.

Fig. 7 is a view similar to Fig. 6 and showing 'the complete die in acontact position.

Fig. 8 is a plan cross section taken on the line 8 8 of Fig. '7.

Fig. 9 is a cross section of the plate holding means taken on the line 99 of Fig. '7 and further illustrates the plate holding means in alowered position relative to the ring diameters also shown in crosssection.

Fig. 10 is a view similar to Fig. 7 illustrating the further reducing ofthe ring treated in Fig. 8 in a smaller die. 5

Fig. l1 is a detail view in perspective and partial cross section of theadapter plate illustrating a locking means.

Referring more in detail to the drawings, Figs. 1-5 inclusive illustrateone form of shouldered 1G anvil, die head and tapered die sleeve. Figs.6-11 inclusive illustrate a somewhat similar taperedv die structureprovided with alternate locking plate structure to takethe place of ananvil and die head.

The material to be reacted on by these structures may comprise a lengthof reversely folded metal ribbon of circular formation or a plurality ofstrips or metal spacers held together in a substantially circular bodyby any suitable means. 2(1)* With reference to the die illustrated inFigs. 1-5 inclusive. II indicates a die sleeve in which the work iseffected-,being constructed with a definite taper for the length of thesleeve and having its inner surface I 2 highly polished toimpart a nish25 to piston ring I3.VA The die sleeve II will be supported by somesuitable base suchas a heavy bolster plate 9 and slidably disposedwithin the die sleeve has been provided an anvil I4 whose periphery willbe of a size to slidably engage in the smaller dimension of the diesleeve II`. Anvil I4 is recessed at its top portion to provide ashoulder I5 which is adapted to receive the piston ring I3 while thelatter is of a circular size large enough to extend over the shoulderVand against the die form an annular punch ring 22, the Outer en e,

cumference of which, subject to clearance, is of the same diameter asthe lower inner periphery of the diesleeve II and shouldered portion ofanvil I4 over which the punch ring is adapted to seat on the pistonTing` I3. A rod 23 is anchored in the 56" top of the press head, notshown, and extends downwardly through thel centerjof the die head, thepunch and the anvil, being provided on its lower end with a head lila.

Bolster plate 9v has an opening Ila for receiv- 5 ing the head Illa,which is also recessed in the anvil I4 at I2a.. I3a is a leather ringfor maintaining the anvil I4 in a fioating position in the die sleeve II.

In operation the piston ring I3, partially closed, is placed in the dieas indicated in Fig. 2. The die punch I9 is brought down into contactwith the piston ring material I3 as shown in Fig. 3. It will be notedthat the upper portion of the inner periphery of the die sleeve istapered upwardly and outwardly so that the piston ring material being inan expanded condition extends outwardly to engage the upper surface ofdie sleeve while the inner periphery of the ring is spread away from theshoulder of the anvil.`

It is to be noted that when the die punch ring is contacting with thepiston ring material, before the die has been fully` closed, l havelprovided for there being a clearance space between the upper surface ofthe anvil and the central surface of the punch bottom. As the die punchis pressed down in contact with the piston ring material the taperedsurface of the piston ring or die sleeve compresses thev piston r'n'f mterial radially until it conforms to the lower inner periphery of thedie sleeve, at which time the inner periphery of the piston ringmaterial becomes tightly seated around the shoulder o' te anvil. As thedie reaches its final position, the clearance space between the punchand anvil is entirely closed up.

During this operation the piston ring material has changed in characterand has now taken a form in which each segment of metal is slightlykeystone shaped throughout.

The action of this die may be said to be twofold as it to some extentradially compresses and then at the end of the stroke delivers a blowwhich finally forms theY ring. This latter action is very important andcalls for Vthe somewhat special structure shown. Y 'e For instance, thepressure required to force anvil l4` thru the die sleeve II, up untilthe anvil bottoms on the bolster plate, maybe relatively small aspossibly a half ton. However, as soon as the anvil bottoms on thebolster place, avery large force acts almost instantaneously like ablow. The pressure at this point may be 150 to 300 tons per square inchon the ring material which is formed and set into the desired shape andall rounded portions are eliminated. To

withstand such pressure, the elements -must made very strong and mustbalance one another as otherwise the die may burst.l Y Also in returningthe punch and anvil a very large'pressure is required which necessitatesthehead construction Illa for gripping the anvil. By the '-utilizationof the disclosed structure the important work done on the ring at theend of the stroke may be effected.

Figs. 6-11 inclusively relate to a structure combined with tapered diesleeves for reacting on a ring made up of folds of revers'ely bentribbon or a plurality of metal strips secured together in some desirablemanner. It is desirable to provide a. substantially large number of suchpieces with their corresponding interstices. To effect such a result, itmay be necessary to start with a ring considerably larger incircumference than the ultimate iinished ring. On this account it may beadvantageous torreduce the ringeither by a single die sleeveor graduallyin succesV with less consideration being given to flattening the topsand bottoms of the ring under pressure. When this is done the anvilmeans is never bottomed to develop a large pressure as illustrated inFigs. l-5 inclusive. The anvil means are continuously floating in thedie sleeves which are themselves modified to present a uniform taperthroughout their length.

If the ring is reduced in one operation, the retaining means forsecuringthe ring within the die sleeve must be of a compressible design to allowfor its passage through an extended die sleeve length. Variousexpansible constructions known in the art may be employed for such apurpose.

The structure about to be described illustrates the use of successivesmaller die sleeve units with holding means designed to carry the pistonring material through the tapered die section without any compressibleconstruction being utilized.

25 indicates a base for receiving a die sleeve as 26 which may beshouldered at 2l to seat on base 25. The base 25 is annually recessed at28 to receive therethrough one side of a locking plate unit generallyindicated by the arrow 29 which is compressibly and slidably mounted bysome -convenient means such as post 36 and spring 3| passing throughsleeve 32. A collar member 33 is engaged adjacent sleeve 32 havingdownwardly extending iianges 34 and upwardly extending iianges 35.Located adjacent collar 33 is provided a retaining ring 36 upon which isfitted an adapter plate 31. The collar 33 is internally threaded Vat 38to receive locking end portion 39 threaded at I6 of a second lockingplate unit generally referred to by the arrow 4I. The second or upperlocking plate unit 4I is provided with a body portion or post 42 securedto a press head 43 by means of a pin 44. 45 indicates a retaining ringsecurely adjacent body portion 42 being somewhat similar to retainingring 36 already described relativetoplate unit 29. Also adjacentretaining ring 45 is an adapter plate 46 similar to adapter plate 3l. I

The retaining ring 45 and adapter plate 46 may be locked into place by'any suitable arrangement such as for instance a pin or stud 4l on bodyportion 42- which is adapted to vertically engage through groove 48 andlock in groove 49, these grooves being more clearly shown in Fig. 11. 1

-In Fig. 6 I have illustrated in vertical cross section two die sleevesections 274 and 26 seated one'within the other with the locking plateunits 4I and 29 out of engagement with a piston ring 56. While thelocking lplate unit 29 has been shown in Fig. 6 in a. raised positionrelative to base 2,5, it should be `understood that it may be depressedand-locked iin a lower position by means of a handle 5I and-'holdingmember 52 for purposes of removal of retaining ring 36 and adapter plate31. i y Y VThe plate unit 4I will `have some convenient means associatedwith the head 43 for its being lowered into engagement with the pistonAring 56 at any point in the die sleeve 24.

The ring 50 may be entered atthe top of die ring 24 by an convenientmeans as for instance being slid out of` a sleeve of the same diameteras the top of die ring 24.

In Fig. '7 the plate unit 29 has been shown in a fully assembled stateto supportand receive ring 56 onV adapter plate 3l.Y Likewise, plateassembly 4I is shown lowered into anoperativeY positionand the lockingend 39 has beenA screwed into the threaded handle 5l.

In the particular operation illustrated in Figs. 6 and '7 the pistonring 50 has been indicated after having been passed thru Yone die step,that is to say it has been tapered to the extent possible in the diesleeve 24, and is about to be carried through the next succeedinglysmaller die, by pressure against the head 43, any suitable type of pressbeing applicable and for convenience not illustrated in the drawings.

It is pointed out that vin theV use of clamping means for passing a ringof material through a tapered sleeve, some limitations maybeencountered. This differs from other situations Where a solid circularbody might be passed through the tapered sleeve or where clamping actionoccurring on both the top and bottom sides of a ring body is notnecessary.

In passing a ring from the top of a downwardly tapered die of anygivendiameter at the top, to the bottom of the die where a smaller portion ofcollar 33 by turning diameter is present, non-contractible means for..

supporting the under side of the ring musthave a diameter of a sizeallowing such means to slidably engage in the smaller dimension, and thering, When at the top of the die, must have a radial Width of such valuethat its inner diameter is less than the .diameter of the supportingmeans as otherwise the supporting means will not be large enough toengage the ring at the top of the die.

Similarly, in passing from one die of a given diameter to a succeedingtapered die of `smaller diameter, the difference 4in dimension betweenthe diameter at the bottom of the rst die and the diameter at the bottomof the second die must be less than the radial widthl of the ring whenit is in the bottom of the rst die.

This is so for the reason that whenever, as is the case here, anon-contractible supporting means is used, for supporting the under sideof a ring to be passed through tapered sleeves, its maximum range ofsupporting area is limited to the diameter of the bottom of the lowersleeve through which the supporting means must slide. Therefore, whilethe work might be contracted to almost any degree, in order to providesupporting means which will engage the under side of the ring in thelarger diameter, and which will itself slide downward through a smallerdiameter, this relation must be preserved.

It should be understood that in operation these die sleeves ar-e made upto rigid specifications so that they are able to effect a denite changein a ring as 50 and with each size of die ring which will be numbered orotherwise indicated, there will be a similarly sized adapter ringlikewise numbered in relation thereto. These adapter plates clamp on tothe ring while it is being reduced and only inward movement of the ringis possible.

In Figs. 9 and 10 there has been illustrated a die sleeve 53 mounted ona die sleeve 54 of uniformly smaller taper. Fig. 9 illustrates therearrangement of die 54 mounted on a still smaller die with the ringbeing held in the lower part of die 54 secured by the locking plateunits 4l and 29 and ready to receive further compressing treatment.

For production Work it is intended that means may be provided formechanically removing the `die ring containing the piston ring at theend by a number of press units. 'I'his is, of course, an alternative toconstructing the plate units of a compressible character whereby asingle long die sleeve length may be utilized.

There are numerous advantages attached to the use of the plate unitssuch as elimination: of all tendency. in the ring to buckle with itspassing through the die sleeve, the simplicity of the engagement withthe ring, the flexibility of handling the die units, and the accuracy ofwork performedin the tapered Yperiphery for any given ring size.particularly sized in relation to the vcorresponding die sleeve,provides a novel, convenient, and expedient means for providing an anviland punch with this type of die structure.

It is considered that the use of combined adapter plates and die sleevesmay be admirably suited yfor other purposes than treating the particularpiston ring material here illustrated. Various changes in proportions,locking means, and the like may be practiced in keeping with the spiritof the present invention.

Having thus described my invention, what I claim is: v

1. A radial finishing and shrinking die for use in treating a circularlength of a reversely folded metal ribbon comprising a base ring, ananvil member, a die punch, and a punch ring portion formed on the lowerextremity of said punch, said base ring having its inner periphery gradually tapered and converging downwardly into a cylindrical portion andadapted to frictionally polish one side of said metal ribbon whendownwardlyiorced thereagainst, said anvil member' The use of theadapters,

being annularly shouldered at Iits upper exportion adapted to seatagainst said anvil and slidably engage in the throated portion of saidring andsaid die punch having an initial clearance between said anvilshoulder and itself corresponding to and for gauging the degree ofreduction of said ribbon.

2. An apparatus for circumferentially reducing and forming a piston ringformed from a reversely bent metal ribbon comprising a ring die portion,an anvil movably disposed within said die portion, and a punch adaptedto engage over said anvil and secure said ring therebetween, said ringdie having its inner periphery uniformly tapered from a greater diameterat the top thereof to a lesser diameter of a size adapted to receivesaid anvil member, occurring a substantial ldistance downwardly of saidinner Areversely bent metal ribbon comprising a ring diel portion, saidring die having its inner uniformly tapered from a greater diameter atthe top thereof to a lesser diameter, of a size adapted to receive ananvil member at the bottom thereof, an anvil locking plate and punchlocking plate for securing said piston ring therebetween, said anvillocking plate and punch locking plate comprising retaining ring andadapter plate elements being sized relative to the circumference of theinner periphery of a respective die at its smallest dimension in such amanner as to be slidably received thereby.

4. An apparatus for circumferentially reducing a ring formed fromreversely bent metal ribbon comprising a ring die portion, said ring diehaving its inner periphery uniformly tapered from a greater diameter atthe top thereof to a lesser diameter of a size adapted to receivesupporting means, an anvil locking plate unit comprising the supportingmeans, and a punch locking plate unit having a threaded locking endadapted to be received in arsmaller threaded opening in the said anvillocking plate unit for the purpose of adjustably securing said'ringtherebetweeen. Y

5. An apparatus for circumferentially reducing a ring element comprisinga ring die member having a tapered inner periphery, means for engagingsaid ring element at its upper and lower sides in said die, said meanscomprising an anvil locking plate unit and a punch locking plate unitreceived Vthrough the bottom and top respectively of the said die, athreaded engaging end extending out of said punch locking plate unitadapted to engage in a similarly threaded opening in said anvil lockingplate unit, and pin means for locking the said units together.

6. An apparatus for circumferentially reducing a ring element comprisinga ring die member having a tapered inner periphery, anvil means adaptedto receive the under side of said ring element in the di-e and punchmeans adapted to engage the upper side of the ring element against theanvil means in the die, the diameter of said anvil means and said punchmeans being of such dimension as to be received through the bottom ofsaid ring die and said diameters also being greater than the innerdiameter of said ring element when the ring element is entered at thetop of said die.

7. An apparatus for circumferentially reducing a ring element comprisinga ring die member having a tapered inner periphery, anvil means adaptedto receive the under side of said ring element in the die and punchmeans adapted to Yengage the upper side of the ring element against Yengage the lower side of said ring element in Ythe die and punch meansadapted to engage th-e ring element at its upper side, and means forclamping the punch means and anvil means together, the diameter of thesaid anvil means being greater than the inner diameter of the said ringelement when the ring is located at the bottom of the first of said diesand said anvil means diameter also being of a size adapted to slidablyengag-e in the bottom of a second succeedingly smaller die.

rIfI-IOMAS A. BOWERS.

